SELECTION AS AN EXPLANATION. 31 
differing more and more widely from each other? To explain such a 
result we must find some other law. I am prepared to show that there is 
.such a law rising out of the very nature of organic activities—a law of 
segregation—bringing together those similarly endowed and separating 
them from those differently endowed. 
(3) Selection does not explain the establishing of unnecessary char- 
acters. 
Again, selection can not explain the divergent transformation of 
forms distinguished from each other in qualities that are not related 
to their success in gaining a living and propagating their kind. As 
illustrations of such transformation may be mentioned beautiful 
arrangements of color that can not be attributed either to natural 
selection or to sexual selection; for example, the patterns with which 
many Hawaiian snails are ornamented, which can not be of use either 
in attracting mates or in gaining a living. 
2. Selection—How far Determined by External Nature. 
Passing to the next point, we inquire whether change in the char- 
acter of the selection affecting any organism is wholly determined by 
change in external nature? Or can change in the character of the 
selection be initiated and maintained through change in the organism, 
without any change in the environment? 
(1) Herbert Spencer’s view.—Spencer distinctly affirms that the latter 
method of change isimpossible. The following are his words: ‘‘That 
there may be continuous changes in organism, there must be continu- 
ous changes in incident forces.” And, again, ‘‘At first, changes in the 
amounts and combinations of external inorganic forces, astronomic, 
geologic, and meteorologic, were the only causes of the successive 
changes undergone by organisms. [In time, however,] the actions 
of organisms on one another became new sources of organic modifica- 
tions.’’ (Principles of Biology, secs. 169, 170.) 
Spencer rests his denial of the freedom of the human will on the 
assumption that all vital activities are predetermined by activities in 
the environment.* It is evident that if our natural powers and our 
present conditions are so determined by the environment that we 
can produce but one set of actions, then no effort on our part, either 
individual or collective, can in the least affect the result; for we can 
not change our circumstances without acting, and our actions are 
already determined by our circumstances. 

* See Principles of Psychology, sec. 220. 
